<ul class="nav nav-tabs">
  <li *ngFor="let item of lists; let i = index" class="nav-item" (click)="changeTab(i)">
    <a class="nav-link" [ngClass]="{'active': active === i}">{{item.name}}</a>
  </li>
</ul>
<div class="tab-content">
  <div *ngFor="let item of lists; let i = index" class="tab-pane p-3" [ngClass]="{'active': active === i}">
    <ng-container [ngSwitch]="i">
      <app-lesson5-one *ngSwitchCase="0"></app-lesson5-one>
      <app-lesson5-two *ngSwitchCase="1"></app-lesson5-two>
      <app-lesson5-three *ngSwitchCase="2"></app-lesson5-three>
    </ng-container>
  </div>
</div>